OSU Extension Service Crop Science Report
EFFECTIVE SLIDES AND OVERHEADS
Or
How to Avoid Embarrassing Yourself
L.C. Burrill, M.E. Mellbye, G.A. Gingrich, A.P. Appleby
This handout was written to help agricultural research and extension workers develop suitable visuals for agricultural audiences. Your involvement as a speaker or organizer at workshops, training sessions, or technical conferences implies an
interest in conveying information to a group of people. Yet,
in spite of repeated pleas and reminders, audiences are still
subjected to horrible and ineffective slides and overheads.
Why? The audience may leave without benefit from your effort if you use poor visual aids or if you present too much information. Here are some tips that will help you tell your
story.
5.
Be careful in using computer-generated tables or graphs as
slides. Multidimensional graphs are often confusing to
the viewer. Some of the slide-making systems fail to fill
the frame and colors often give poor contrast. Dark reds,
greens, and blues on a dark background cannot be seen.
6.
Vericolor film and a selection of filters will produce sharp
high-contrast print slides and can be processed by most
photo labs in one day or less.
7.
Arrange your text or graphics in a 3 by 5 ratio to fit a
35mm slide. A simple example:
Change
A presentation does not necessarily result in the communication that you wish to take place. Slides and overheads are effective communication aids only if they are readable and
simple.
Weed Control in Wheat
to
Slides
Weed Control
in
Wheat
Slides are the preferred medium because they can be enlarged
more by the projector than an overhead. Here's some guidelines on how to make your slides effective.
1.
Limit the amount of information, probably no more than
10 to 12 pieces of data on one table.
2.
Use simple language and names.
3.
Make sure the letters and numbers are readable. Hold the
slide up and read it with the naked eye. If you can't,
don't use it!
4.
Divide tables of data into two or more slides or leave
some out and provide the full report as a handout.
L.C. Burrill, Extension Weed Control Specialist, Department
of Crop and Soil Science, Oregon State University, M.E.
Mellbye, Extension Agent, Linn County; G.A. Gingrich, Extension Agent, Marion County; A.P. Appleby, Professor, Department of Crop and Soil Science, Oregon State University,
Corvallis, OR 97331-3002.
EXT/CRS 90
6/92
8.
When shooting slides of print, try to fill the slide frame if
there is any doubt about the readability of your slides. If
you don't have a macro lens, buy extension tubes, which
are much cheaper.
Overheads
Overhead transparencies are fast to prepare and can be used in
lighter rooms than slides to encourage discussion. They have
few other attributes.
1.
Always enlarge the subject with a copy machine or printer
before making the overhead. Standard size print is unacceptable. Don't do it! You will embarrass yourself and
your organization!
2.
[Poor]
Large print with colored felt pens will produce readable
overheads that are far superior to small block type.
The Effect of Fungicides and Cerone on Septoria and
Yields in three varieties of Winter Wheat.
3. Never make overheads of large tables and graphs. The
print cannot be seen. Remember, the smallest character
should be 3/16 inch for a small group and 3/8 inch for a
large group. You are trying to communicate, so print
should be easily read from the back of the room. If the
audience has to squint, the print is too small.
Treatment
Hill 81
(bu/acre)
Check
Cerone
Tilt
General Rules of Thumb
1.
Color. The most readable color combinations are listed
below. Other combinations are consistently less appealing
visually. The colors should be presented in their primary
hues.
Tilt + Cerone
LSD (0.5)
The Best Colors
3.
4.
5.
Remember your take-home message. Don't show all your
data. Simplify, condense, summarize! If you need to
show data in a table, limit yourself to as few numbers as
possible. Never exceed 10 to 12. Don't even think of
photographing a table from a report. Often, data can be
effectively communicated verbally in combination with a
good picture. For example, if a chemical caused dramatic
crop injury, show the injury and just report that injury
was significant.
Don't teach statistics. Don't take up space on slides and
overheads with statistical gobbledygook! It may be better
to leave statistical measures off visuals, especially at
grower meetings, and just verbally report that it's significant. Do not subject farmers to tables of non-significant
data. Simple statistics may be justifiable at scientific
meetings but even there the inclusion of experimental design and statistical analysis is best left to the written
report.
140.1b
129.7c
163.5a
159.9a
8.5
142.3b
140.0b
158.1a
156.8a
4.3
Cerone and Fungicides for Septoria on Wheat
Hill 81 Malcolm Stephens
Control
Cerone
Tilt
Never use more than three colors; two is usually better
Terminology. Use English units and common names to
describe treatments for grower audiences. For example:
2 qts/ac Nortron rather than 2.2 kg/ha of ethofumesate.
Use metric if required at professional meetings. Make
two slide sets.
135.6a
130.2c
134.0ab
133.5abc
3.4
[Better]
Blue and White
Green and White
Red and White
Black and White
Black and Yellow
2.
Variety
Malcolm Stephens
Tilt + Cerone
136
130
134
134
140
130
164
160
142
140
158
157
6.
Make sure that print on graphs can be read. It is usually
easy to see the graph but many people fail to enlarge the
print on the graph.
7.
Time. This depends entirely on the slide or overhead.
Some need 5 seconds, others can be discussed for a minute
or longer. A common mistake is spending too little time
on key visual aids.
8.
Intersperse data slides with appropriate photos or illustrations of materials, events, locations, or even some humor
or philosophy.
9.
Readability. Words with upper and lower case letters are
more readable than those done in capitals. Use bold type,
not capitals, italics, or stylized letters. For example:
Stem Rust is better than STEM RUST, or stem rust, or
Stem Rust.
10. Words and Lines. Title slide: Limit to ten words. Lines
on a slide: Five or less.
11. Conclusion. Use a conclusion slide to nail down your
take-home message.
Round to whole numbers.
Following is an example of how to improve a data table.
12. Communication is the goal.
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